Technically, the Repeater widget is a ContainerWidget whose children are
Repeater.RepeaterRows, and the RepeaterRows in turn are ContainerWidgets
containing the actual repeated widgets. However, in practice, you won't need
to use the RepeaterRow widget directly.

readFromRequest

Lets this widget read its data from a request. At this point the Widget
may try to convert the request parameter to its native datatype (if it
is not a string), but it should not yet generate any validation errors.

generateSaxFragment

Generates an XML representation of this widget. The startDocument and endDocument
SAX events will not be called. It is assumed that the prefix for the Woody namespace
mentioned in Constants.WI_PREFIX is already declared (by the caller or otherwise).